Web CRUD apis in asp.net core 7.0

First, make sure you have the required NuGet packages installed: `Microsoft.Azure.Cosmos`, `Microsoft.Azure.Cosmos.Fluent`, and `Microsoft.Extensions.Configuration.AzureKeyVault`.

1. Create a `Product` class to represent your data model:

public class Product
{
    public string Id { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }
}

2. Create an interface to define the operations for working with the Cosmos DB:

public interface IProductRepository
{
    Task> GetAllProductsAsync();
    Task GetProductByIdAsync(string id);
    Task AddProductAsync(Product product);
    Task UpdateProductAsync(string id, Product product);
    Task DeleteProductAsync(string id);
}

3. Implement the `IProductRepository` interface using the Cosmos DB SDK:

using Microsoft.Azure.Cosmos;

public class CosmosDbProductRepository : IProductRepository
{
    private readonly Container _container;

    public CosmosDbProductRepository(CosmosClient cosmosClient, string databaseName, string containerName)
    {
        _container = cosmosClient.GetContainer(databaseName, containerName);
    }

    public async Task> GetAllProductsAsync()
    {
        var query = _container.GetItemQueryIterator();
        var products = new List();

        while (query.HasMoreResults)
        {
            var response = await query.ReadNextAsync();
            products.AddRange(response.Resource);
        }

        return products;
    }

    public async Task GetProductByIdAsync(string id)
    {
        try
        {
            ItemResponse response = await _container.ReadItemAsync(id, new PartitionKey(id));
            return response.Resource;
        }
        catch (CosmosException ex) when (ex.StatusCode == System.Net.HttpStatusCode.NotFound)
        {
            return null;
        }
    }

    public async Task AddProductAsync(Product product)
    {
        ItemResponse response = await _container.CreateItemAsync(product, new PartitionKey(product.Id));
        return response.Resource;
    }

    public async Task UpdateProductAsync(string id, Product product)
    {
        ItemResponse response = await _container.UpsertItemAsync(product, new PartitionKey(id));
        return response.Resource;
    }

    public async Task DeleteProductAsync(string id)
    {
        try
        {
            await _container.DeleteItemAsync(id, new PartitionKey(id));
            return true;
        }
        catch (CosmosException ex) when (ex.StatusCode == System.Net.HttpStatusCode.NotFound)
        {
            return false;
        }
    }
}

4. Create a controller to handle the API endpoints:

[ApiController]
[Route("api/products")]
public class ProductController : ControllerBase
{
    private readonly IProductRepository _productRepository;

    public ProductController(IProductRepository productRepository)
    {
        _productRepository = productRepository;
    }

    [HttpGet]
    public async Task>> GetAllProducts()
    {
        var products = await _productRepository.GetAllProductsAsync();
        return Ok(products);
    }

    [HttpGet("{id}")]
    public async Task> GetProductById(string id)
    {
        var product = await _productRepository.GetProductByIdAsync(id);
        if (product == null)
            return NotFound();

        return Ok(product);
    }

    [HttpPost]
    public async Task> CreateProduct(Product product)
    {
        var createdProduct = await _productRepository.AddProductAsync(product);
        return CreatedAtAction(nameof(GetProductById), new { id = createdProduct.Id }, createdProduct);
    }

    [HttpPut("{id}")]
    public async Task UpdateProduct(string id, Product product)
    {
        var updatedProduct = await _productRepository.UpdateProductAsync(id, product);
        if (updatedProduct == null)
            return NotFound();

        return NoContent();
    }

    [HttpDelete("{id}")]
    public async Task DeleteProduct(string id)
    {
        var result = await _productRepository.DeleteProductAsync(id);
        if (!result)
            return NotFound();

        return NoContent();
    }
}

Note: You will need to configure the Cosmos DB connection and set up dependency injection for the `CosmosClient` and `IProductRepository` in the ASP.NET Core Startup class.

That's it! You now have a basic CRUD API using Cosmos DB in ASP.NET Core 7.0. You can test the API endpoints using tools like Postman or any other HTTP client.